package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

//过滤器，检查用户是否已经登录
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER =new AntPathMatcher();


    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        /**
         * 1、获取本次请求的UR才
         * //2、判断本次请求是否需要处理//3、如果不需要处理，则直接放行
         * //4、判断登录状态，如果已登录，则直接放行//5、如果未登录则返回未登录结果
         */
        //1、获取本次请求的url
        String requestURI = request.getRequestURI();

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };
        //2、判断本次请求是否需要处理
        boolean check = check(urls, requestURI);
        //3、如果不需要处理，直接放行
        if (check){
            filterChain.doFilter(request,response);
            return;
        }
        //4、判断登录状态，放行
        if (request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录，用户Id：{}",request.getSession().getAttribute("employee"));

            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request,response);
            return;
        }
        //4.1、判断登录状态，放行
        if (request.getSession().getAttribute("user")!=null){
            log.info("用户已登录，用户Id：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }
        //5、如果未登录则返回未登录结果
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;


    }


    //路径匹配，检查请求是否需要放行
    public boolean check(String[] urls,String requestURL){
        for (String url : urls){
            boolean match = PATH_MATCHER.match(url, requestURL);
            if (match){
                return true;
            }
        }
        return false;
    }


}
